<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>esnext</title>
    <style>
      body {
        text-align: center;
        margin-top: 100px;
        height: 100px;
        width: 100px;
        border: 1px solid #000;
      }
      head {
        display: block;
        height: 100px;
        width: 100px;
        border: 1px solid #000;
        margin-bottom: 100px;
      }
      .container {
        overflow: hidden;
      }
      .container::before {
        /* display: inline-block;
        content: ""; */
      }
      .container::after {
        display: block;
        content: "";
        clear: both;
      }
      .container div {
        width: 100px;
        height: 100px;
        border: 1px solid #000;
        margin: 100px;
      }
    </style>
  </head>

  <body>
    <div
      id="process-bar"
      style="background-color: aqua; width: 0; height: 20px"
    ></div>
    <button id="btn">开始</button>
    <div class="container">
      <div>长风几万里</div>
    </div>
    <div class="container">
      <div>吹度玉门关</div>
    </div>
  </body>
</html>
